When I was working in watercolor years ago, one of the things I predetermined was the intensity of the colors. Back then I determined the intensity based on value. As an example I might make all the mid-values basically intense (MVI), the lighter values dull (LVD) and the dark values dull (DVD). That left me several options:

I know, I know you might not want to do that but it is an interesting design principle. It is good I think for us to try new things. It is a creative thing I believe So That Is The Question - Intensity or No Intensity?